JPS59165688A - Thermal transfer recording material - Google Patents

Abstract

PURPOSE:To provide a thermal transfer recording material capable of easily obtaining a color gradation by controlling heating time, comprising a transfer paper supporting a sublimable dye or the like thereon and a transferred paper obtained by coating a surface of a cellulose paper with a thermoplastic polymer material. CONSTITUTION:A sublimable dye and/or an evaporable dye sublimed or evaporated at a temperature of preferably 80-220 deg.C (e.g., C.I. Disperse Yellow used in thermal transfer printing), a binder and a solvent or the like are mixed with each other, and the resultant mixture is applied onto a base such as a condenser paper to obtain a transfer paper. On the other hand, a surface of a cellulose paper is coated by a thermoplastic polymer material having a glass transition point of preferably not higher than 250 deg.C, preferably followed by covering the thus coated surface by a releasable substance (e.g., a silicone resin) to produce a transferred paper. The transfer paper and the transferred paper are combined with each other to obtain the objective recording material.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal transfer recording material. More specifically, it relates to a thermal transfer recording material consisting of a transfer paper that carries a sublimable or vaporizable dye, and a transfer paper that is dyed with a dye that sublimes or vaporizes by applying heat to the transfer paper from the outside. It is. That is, the present invention relates to a thermal transfer recording material comprising a transfer paper carrying a sublimable dye or a vaporizable dye, and a transfer paper receiving the dye which sublimes or vaporizes by heat. is a thermally transferable recording material characterized in that the surface is cellulose paper, and the surface facing the transfer paper and receiving the dye during use, that is, the surface to be transferred, is coated with a thermoplastic polymer material. This thermal transfer recording material further comprises the surface of the transfer paper coated with the thermoplastic polymeric material further coated with a releasable substance.

Conventionally, heat-sensitive recording methods include a method in which a recording paper containing a color-forming dye such as a leuco dye and an acidic substance is used to develop color using a thermal head, and a dye or pigment is supported on a heat-melting wax or rough-in material. A method is known in which dyes and the like are transferred and recorded from transfer paper onto plain paper by thermal melting.

The former is inexpensive and suitable for recording two or more colors, but is not suitable for producing more than one color.

The latter can produce several colors and produce clear colors, but is not suitable for recording intermediate colors or gradations.

In melt-type thermal transfer, the melting point of the ink is around 70°C and the temperature range is narrow, so the depth method etc. is used to increase the number of dots per unit area to create gradations, making it possible to express pseudo-gradations. Although this is expected, extremely high resolution is required for heating elements such as thermal heads. On the other hand, in the present invention, the transfer of the dye from the transfer paper to the receiving paper is substantially carried out by sublimation or vaporization, which occurs more slowly than the transfer due to thermal melting as described above, so the heating temperature Alternatively, by controlling the heating time, it is possible to easily obtain a desired color density gradation.

Thermal transfer printing using sublimation or vaporization phenomena has already been widely put into practical use in the dyeing industry.

In this case, the desired design is printed onto paper or heat-resistant film using a transfer ink made from an appropriately selected dye, and the transfer paper is attached. The two sides are placed one on top of the other, and heat is applied from the outside to transfer the design printed on the transfer paper onto the cloth, completing the printing process. The basic principle is that when heated, the dye sublimes or vaporizes from the transfer paper and attaches to the fiber surface. At this time, the cylindrical molecular chains that make up this fiber are softened by the same heating, so the dye does not condense. The dye diffuses inside the fiber and adheres to it as it cools. As can be seen from this, synthetic polymer fibers with low glass transition points, such as polyester, polyacrylic, and polyvinyl acetate, can be printed well by sublimation or vaporization heat transfer printing, but natural fibers such as cotton cannot be printed in this way. Printing is difficult. For this reason, in order to print cotton etc. using this method, it must be chemically treated such as acylation,
Alternatively, methods of modifying the fiber surface by resin treatment such as block polymerization, or conversely, using a reactive dye that reacts with the hydroxyl groups of cellulose, etc., have been considered. The purpose of the present invention is to transfer sublimable or vaporizable dyes onto cellulose paper to obtain full-color images based on knowledge of such textile printing technology.

Based on the above principle, if synthetic paper made of filaments of synthetic polymers such as polyester, polyacrylic, or vinyl acetate is used as transfer paper, thermal transfer using dye sublimation or vaporization can be used. Although recording materials are easily made, these synthetic papers are more expensive than cellulose and have a different feel from cellulose paper, so there is a demand for transfer paper based on cellulose paper. If cellulose paper is used as is, thermal transfer using sublimation or vaporization of the dye is difficult, as is the case with transfer printing to cotton cloth. As a result of extensive research, the inventors have found that by coating the surface of cellulose paper with a thermoplastic polymer material, it is possible to inexpensively produce transfer paper that has good transferability without impairing the feel of cellulose paper, and that the coating The inventors have now discovered that adhesion between the transfer paper and the receiver paper can be prevented by further coating the surface with a release material such as a silicone resin.

Examples of thermoplastic polymer substances used in the present invention include Eva polyacrylic ester, polyethylene terephthalate, polyamide, polyvinyl acetate, polyolefin, polyacrylamide, polyvinyl alcohol, styrene-butadiene copolymer, ethylene-vinyl acetate copolymer, and polyvinyl butyral. , polyurethane resins, natural rubber latex and modified products thereof, synthetic polysaccharides such as cellulose triacetate, etc., and those having a glass transition point of 250° C. or lower are preferable. These polymeric substances are used in an appropriate form such as an aqueous colloid, an aqueous solution, or an organic solvent solution, and are applied to cellulose paper by, for example, a roll, spray, or other arbitrary method, and then dried. Although the transfer paper produced in this manner can be used as is, it often adheres to the transfer paper and becomes difficult to separate. The inventor solved this difficulty by further applying a thin layer of a releasable substance to the surface of the transfer paper coated with the thermoplastic polymer material.

In dye sublimation heat transfer printing in the dyeing industry, it is said that transfer printing becomes impossible if the synthetic resin cloth that is the transfer target fabric is processed with a substance such as silicone resin, but the inventor surprisingly discovered that It has been found that even if a release material such as a silicone resin is further applied to the surface of cellulose paper coated with a thermoplastic polymeric material, the thermal transfer of the dye to that surface is not inhibited at all. The releasable material used here is preferably a resin that has good dye permeability, high heat resistance, and strong releasability, such as silicone resin,
Examples include, but are not limited to, fluororesins, epoxy resins, urea resins, and melamine resins. These resins are used in an appropriate form such as an aqueous colloid, a grease, an organic solvent solution, or a candy made by mixing a base resin and a hardening agent, and are applied by, for example, a roll, spray, or other arbitrary method.

The transfer paper used in the present invention is obtained by coating a base material with an ink consisting of a dye binder and a solvent and drying it. Further, if necessary, a release layer may be provided on the dye coating film. The base material is preferably a sheet or film with good heat resistance and thermal conductivity and low ink absorption, such as capacitor paper, tracing paper, paraffin paper, heat-resistant synthetic resin film, etc. Ru. The thickness depends on the thermal conductivity of the substrate and the desired transfer speed. Unlike transfer paper for thermal transfer printing, this transfer paper does not have a pattern, and one type of ink is uniformly applied to one side of the transfer paper. The ink consists of a finely powdered sublimable dye or/and vaporizable dye, a binder, and a solvent, and a dispersant is also used to stabilize the ink and prevent the dye from coming off due to scratches or rubbing on the surface of the transfer paper. It is preferable. It is said that dispersants interfere with the sublimation or vaporization of dyes9, but such a phenomenon is not observed at all in the present invention.

A sublimable dye or a vaporizable dye is a dye that has a temperature of 50C or more and preferably sublimates or vaporizes at a temperature of 80°C to 220°C. Mainly disperse dyes, cationic dyes,
Those used in thermal transfer printing, such as oil-soluble dyes, can be used. Such dyes include, for example, C3, Disnos Yellow 1°3, 7. 8. 9.13
．． 16.23.41.42.49.54゜59,60.
61.64. 116 etc., C0■, Desno Mother - S Orange 3. 7.15.21.25, etc., 1. 4. 9.11.13.1
5.17.41.55゜59, 60.65.73.83
etc., 0. Engineering, Desno Mother Q Violet's 1. 4
．． 12.18.23.26.27 etc., 0.technique, Solvent Red 23.24.25.27 etc., 0.technique,
Basic Yellow 11.13.29 etc. 0, I
, Basic Orange 21, 0. engineering, basic red 13, etc., C0■, basic green 1, 4, etc., C0■, basic blue 5, etc.
Or Sumikaron Black B-B, Same Shi<8-
2GL, Eisen Cachiron Black GH, Resilence
Examples include, but are not limited to, black TR-WN liq, etc.

These dyes can be used singly, but several types can also be mixed to create an ink suitable for expressing a desired color tone or gradation. Alternatively, for example, three types of ink can be applied using dyes of three colors, cyan, magenta, and yellow separately, and three types of transfer paper manufactured by coating them can be sequentially used to create an arbitrary image on the transfer paper. It is possible to print tonal and tonal images or strokes. Binders constituting the ink include natural and synthetic polysaccharides and their salts, such as starch, gakistrin, hydroxyalkyl celluloses such as ethyl cellulose and 2-hydroxyethyl cellulose,
OMO, etc., and synthetic polymer materials such as polyvinyl alcohol, styrene-butadiene copolymer, polyvinyl alkyl ether-maleic anhydride copolymer, acrylic resin, polyester resin, vinyl acetate resin, nylon, etc. Although resins, polyolefin resins, etc. can be used, binders with low thermoplasticity are desirable.

The solvent does not matter whether it is water or a non-aqueous solvent as long as it dissolves or disperses the dye and/or binder and exhibits a fixing ability. In addition to these, sublimation accelerators such as nitrotoluene, adamantane, etc. can be added to the ink, and an antifoaming agent can also be added.

Example 1 A No. 0.3 wire rod was used on white high-quality paper (Kishu Paper Co., Ltd. "Kanasa", 65 f/m') [Sevian A-463].
5J (manufactured by Daicel Chemical Industries, Ltd., acrylic acid ester emulsion) was coated and dried at Seki° C. for 1 minute (coating amount after drying: 10 f/m') to produce a transfer paper.

On the other hand, holvinyl alcohol [manufactured by Unitika, UP240]
To a solution of 35.0 parts of G dissolved in 45.0 parts of water, 2.5 parts of each of the three types of disperse dyes listed below were separately added and thoroughly dispersed using a homogenizer to prepare three types of ink.

1, Red, a, Technique, Disperse Red (A) (Sumikaron Red B-FBL) 2, Blue, C1 ■,
Daysno Soichisu Blue 26 (Sumikaron Blue E
-BR) 3, yellow, 0. (Kimberly-01ark)
Manufactured by Kraft Capacitor TisθUθ
, 18μ thick) and dried to produce three types of transfer paper.

Lay the coated surface of the above transfer paper on the coated surface of these three types of transfer paper, and use a dry heat test@Shin [Suga Test Instruments Model DH-1] to 100℃ to 210℃ from the transfer paper side. between 10℃
Heat was applied at intervals of 5 seconds each to transfer the material to the receiving paper. Clear color images of red, true color, and yellow, which went from light to dark as the temperature rose from low temperature, were transferred to the transfer paper. Table 1 shows the color depth and intensity of the color images measured using a Macbeth reflection densitometer (RD-514).

In this sublimation transfer step, once every few times the transfer paper and the paper to be transferred adhere to each other, making it difficult to separate them.

11-Table 1 Reference Example The same three types of transfer paper as in Example 1 were used, and the same high-quality paper as in Example 1 was used as the transfer paper [Sevian A-4635J].
The same transfer treatment as in Example 12-1 was performed at 200° C. without coating. As a result, in all three colors, the color images on the transfer paper were much lighter, duller, and less clear than the color images in Example 10 at 200°C. Table 2 shows the color tones measured using a pigment meter.

Table 2 Example 2 [Sevian A-4] of the transfer paper manufactured in Example 1
A transfer paper was prepared by applying silicone grease (Shin-Etsu Chemical Co., Ltd., H-Ko VAO-G) to the coated surface of 635J at a rate of about 1 g/rd before application. Sublimation transfer similar to that in Example 1 was performed using this transfer paper and the transfer paper in Example 1. The tone and color quality of the color image obtained on the transfer paper were almost exactly the same as in Example 1.

During this sublimation transfer, no adhesion occurred between the transfer paper and the paper to be transferred, and the separation was performed extremely smoothly.

Example 3 Pyronal MD-1200 was applied to the same high-quality paper as in Example 1.
J [: Toyobo ■, glue-like water-based polyester resin] was applied using a No. 0.3 wire iron, and heated to 150℃~
It was dried at 160°C for 1 minute. Next, apply epoxy resin [High Resin M-404 manufactured by Inu Nippon Shikizai Kogyo ■] to the coated surface.
0RJ 1 part and its hardening agent “Hi-Resin M-4040”
A mixture with 3 parts of HJO] was coated using a No. 0.1 wire rod and allowed to stand at room temperature for a period of time to harden, thereby producing a transfer paper.

On the other hand, 2.5 parts each of oil-soluble dyes C0, Solvent Yellow 16 and C1, Solvent Red were added to hydroxypropyl cellulose C Japan 1, HPO-
H] 1.5 parts and 48.5 parts of dimethylformamide to prepare two kinds of inks, and these were mixed in the same manner as in Example 1 with a condenser paint. - and dried to produce two types of transfer papers.

The coating direction of the transfer paper was superimposed on the coated surface of these transfer papers, and the temperature was measured from the transfer paper side using the thermal tester used in Example 1.
Heated at 00°C for 1 minute. Clear, dark yellow and red color images were transferred to the transfer paper, respectively. Further, no adhesion occurred between the transfer paper and the transfer paper, and the two were easily peeled off.

Example 4 OoI of cationic dye, Basic Niro 112.5
1 part and 1.2 parts of carboxymethyl cellulose (manufactured by TAR Pharmaceutical, Celodan BP) were dissolved in 48.8 parts of water, and this was applied to condenser paper 15-4' in the same manner as in Example 1 for transfer. Created a paper.

This transfer paper was combined with the transfer paper of Example 2 and heated to 200°C.
The same transfer process as in Example 1 was performed for 1 minute. A clear yellow color image was observed on the transfer paper. Further, the transfer paper and the transfer paper did not adhere to each other and could be easily peeled off.

Example 5 Using the same transfer paper and transfer paper as used in Example 2, transferred color images in tones other than red, blue, and yellow were obtained in the following manner.

That is, a red transfer paper was placed on top of a yellow image on a transfer paper obtained by transferring using a yellow transfer paper, and an orange color image was obtained. Similarly, a blue transfer paper was placed on top of the yellow image and transfer was performed to obtain a green image. In these experiments, the transfer was performed using the same heating device as in Example 1.
Heating was performed at 0° C. for 5 seconds.

−16=

Claims (1)

[Claims] 1. A thermal transfer recording material comprising a transfer paper carrying a sublimable dye or/and a vaporizable dye and a transfer paper receiving the dye, wherein the transfer paper is cellulose paper. 1. A thermal transferable material, characterized in that the surface to be transferred is coated with a thermoplastic polymer material. 2. The thermal transfer material according to claim 1, wherein the surface of the transfer paper coated with the thermoplastic polymeric material is further coated with a releasable substance.